Consider the facts and piece them together, trying to explain them:

Yeshua died as a young man - contrast with other religious founders:
Confucius-72
Gautama the Buddha -80
Muhammad -62
Yeshua died at 33, spent only three years in the public eye, never wrote a book, left nothing but a group of demoralized followers who had gone back to their day job - fishing! How do we account for the meteoric rise of the church? The Bible’s answer - Yeshua was raised from the dead.
In direct contrast with other religious founders:Confucius-72 Gautama the Buddha -80 Muhammad -62 Yeshua died at 33, spent only three years in the public eye, never wrote a book, left nothing but a group of demoralized followers who had gone back to their day job - fishing! How do we account for the meteoric rise of the church? The Bible’s answer - Yeshua was raised from the dead.

Several people claimed to have seen him over a period of 40 days after he had died.
25 years later, the apostle Paul could write that on one occasion within that 40 day period, 500 people saw him, ‘many of whom are still alive’ 1 Corinthians 15:5-8 "And that he was seen of Cephas, then of the twelve: 6 After that, he was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep. 7 After that, he was seen of James; then of all the apostles. 8 And last of all he was seen of me also, as of one born out of due time."

In other words, he is telling these new Believers they can check it out for themselves. The fact that different people, of different temperament, in different situations, claimed to have seen and heard the risen Yeshua, rules out that hallucination was at work.